In the prior art, it is known that to secure wood and aluminum profiles using rotating, profile connection keys.
Examples of these systems have been disclosed in the documents FR,A,2516122 (ZAPP), AT,B,308361 (SOMMER) and PCT/IT90/00090 (ARCHIMEDE PROGETTI). The first two solutions reveal a profile connection key with two opposite key-shaped tapering flanges, with a central connection neck able, by means of the two opposite tapers of the flanges, to enable the coupling of profiles with a direct axial insertion (orthogonal in respect to the groove of the profile) with a successive connection by rotating 90.degree. the same profile connection key.
The third solution provides instead, on one side, a key-shaped tapered flange and on the other a disc-shaped flange, which must be previously inserted head first inside one of the grooves of the profiles and then coupling the second profile by means of a direct orthogonal coupling and a successive rotation of 90.degree. of the profile connection key.
These solutions, even if they, provide the possibility to couple two profiles generally inside the respective dovetail or undercut groove, have the drawback that they are free to move or slide inside the respective groove or have a slight interference, consequently:
if there is interference on one side and free scrolling on the other, once inserted in the groove on the side of profile without interference, it is not possible to keep them in a position for the coupling with the second profile unless we make a horizontal assembly during the assembly or vertical re-assembly and then proceed to the re-spacing and fixation one at a time; PA1 if they have interference on both sides, then there is a difficulty in positioning for slippage.